Hm, well I am going to say this doesn't look like a scheduling issue, it seems like something might be failing. It could be some sort of retries are happening, maybe due to the "string" column type, but I am not sure why you get that as a data type.
What I can do on my side is set up Varada and try to use that connector. One thing you may want to look into, if it isn't too much work for you to do, is upgrading your Trino version. I am currently using Trino version 384.